Dishwashers, in particular commercial dishwashers, in the form of a box-type warewasher (aka batch-type or door-type warewasher) may, by way of example, be hood-type warewashers or front-loader warewashers. In both cases, wares are loaded into a treatment space in batch-form through an opening, wash and rinse operations are applied to the wares sequentially while the wares sit in the same, single treatment space or zone, and the wares are then removed from the treatment space, again in batch-form, to make room for a next batch/load of ware. Front-loader warewashers, by way of example, may be under-counter machines or top-counter machines or built-in-counter machines. A given box-type machine may be constructed to handle a variety of ware types or to specifically handle primarily certain types of ware (e.g., glasswashers or pot and pan washers).
Box-type machines that wash and rinse with hot water (e.g., 150°-160° F. wash & 180° F. rinse) commonly require a ventilation system at the installation site to remove the hot, moist air emitted from the warewasher after a cycle is completed. After the ware is cleaned and sanitized, the door is opened releasing a plume of hot, moist air into the room. As a result, vent hoods are commonly required to eliminate this excess heat and humidity.
For some locations it is undesirable to install a ventilation hood due to the cost or building constraints. In these cases the customer may purchase a low temperature warewasher to eliminate the need. However, most customers prefer the performance achieved by high temperature machines.